Skip to content

K
Kernel

openeuler / Kernel
接近 2 年 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 21 6月, 2012 1 次提交
    • D
      pch_uart: Add eg20t_port lock field, avoid recursive spinlocks · fe89def7
      由 Darren Hart 提交于 
      pch_uart_interrupt() takes priv->port.lock which leads to two recursive
spinlock calls if low_latency==1 or CONFIG_PREEMPT_RT_FULL=y (one
otherwise):

pch_uart_interrupt
  spin_lock_irqsave(priv->port.lock, flags)
  case PCH_UART_IID_RDR_TO (data ready)
  handle_rx_to
    push_rx
      tty_port_tty_get
        spin_lock_irqsave(&port->lock, flags) <--- already hold this lock
        ...
      tty_flip_buffer_push
        ...
        flush_to_ldisc
          spin_lock_irqsave(&tty->buf.lock)
            spin_lock_irqsave(&tty->buf.lock)
            disc->ops->receive_buf(tty, char_buf)
              n_tty_receive_buf
                tty->ops->flush_chars()
                uart_flush_chars
                  uart_start
                    spin_lock_irqsave(&port->lock) <--- already hold this lock

Avoid this by using a dedicated lock to protect the eg20t_port structure
and IO access to its membase. This is more consistent with the 8250
driver.  Ensure priv->lock is always take prior to priv->port.lock when
taken at the same time.

V2: Remove inadvertent whitespace change.
V3: Account for oops_in_progress for the private lock in
    pch_console_write().

Note: Like the 8250 driver, if a printk is introduced anywhere inside
      the pch_console_write() critical section, the kernel will hang
      on a recursive spinlock on the private lock. The oops case is
      handled by using a trylock in the oops_in_progress case.
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>
CC: Tomoya MORINAGA <tomoya.rohm@gmail.com>
CC: Feng Tang <feng.tang@intel.com>
CC: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fe89def7
  3. 19 4月, 2012 1 次提交
    • T
      pch_uart: Fix dma channel unallocated issue · af6d17cd
      由 Tomoya MORINAGA 提交于 
      This driver anticipates pch_uart_verify_port() is not called
during installation.
However, actually pch_uart_verify_port() is called during
installation.
As a result, memory access violation occurs like below.

0. initial value: use_dma=0
1. starup()
    - dma channel is not allocated because use_dma=0
2. pch_uart_verify_port()
    - Set use_dma=1
3. UART processing acts DMA mode because use_dma=1
     - memory access violation occurs!

This patch fixes the issue.

Solution:
Whenever pch_uart_verify_port() is called and then
dma channel is not allocated, the channel should be allocated.
Signed-off-by: NTomoya MORINAGA <tomoya.rohm@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      af6d17cd
  5. 10 4月, 2012 9 次提交
  7. 06 4月, 2012 1 次提交
    • S
      simple_open: automatically convert to simple_open() · 234e3405
      由 Stephen Boyd 提交于 
      Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op.  This leads to a
proliferation of the default_open() implementation across the entire
tree.

Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().

This replacement was done with the following semantic patch:

<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}

@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      234e3405
  9. 21 3月, 2012 1 次提交
  11. 10 3月, 2012 5 次提交
  13. 10 2月, 2012 3 次提交
  15. 16 11月, 2011 5 次提交
  17. 31 10月, 2011 1 次提交
  19. 23 9月, 2011 1 次提交
    • J
      TTY: serial, fix includes in some drivers · ee160a38
      由 Jiri Slaby 提交于 
      linux/tty_flip.h is included in linux/serial_core.h. But this may (and
will) change in the future. Then we would get build errors such as:
.../tty/serial/max3107.c: In function ‘put_data_to_circ_buf’:
.../tty/serial/max3107.c:149:2: error: implicit declaration of function ‘tty_insert_flip_string’

So fix all the drviers which call tty flip buffer helpers to really
include linux/tty_flip.h. And also make sure that those include
linux/tty.h when operating with struct tty_struct.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      ee160a38
  21. 23 8月, 2011 1 次提交
  23. 09 7月, 2011 2 次提交
  25. 16 6月, 2011 1 次提交
  27. 08 6月, 2011 1 次提交
  29. 25 5月, 2011 1 次提交
    • A
      drivers/tty/serial/pch_uart.c needs slab.h · 023bc8e7
      由 Andrew Morton 提交于 
      alpha allmodconfig:

  drivers/tty/serial/pch_uart.c: In function 'dma_handle_tx':
  drivers/tty/serial/pch_uart.c:873: error: implicit declaration of function 'kzalloc'
  drivers/tty/serial/pch_uart.c:873: warning: assignment makes pointer from integer without a cast
  drivers/tty/serial/pch_uart.c: In function 'pch_uart_init_port':
  drivers/tty/serial/pch_uart.c:1403: warning: assignment makes pointer from integer without a cast

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      023bc8e7
  31. 11 5月, 2011 1 次提交
  33. 15 3月, 2011 1 次提交
  35. 23 2月, 2011 4 次提交